Judging by demand, many natural perfumes are available in totally inadequate quantities. For example, 5,000 kg of rose blossoms are required to obtain 1 kg of rose oil. The consequences are extremely limited annual world production and a high price. Accordingly, it is clear that there is a constant need in the perfume industry for new perfumes with interesting fragrance notes in order to extend the range of naturally available perfumes, to make the necessary adaptations to changing fashion trends and to be able to meet the steadily increasing demand for odor enhancers for products of everyday use, such as cosmetics and cleaners.
Accordingly, it is clear that there is a constant need in the perfume industry for new perfumes with interesting fragrance notes in order to extend the range of naturally available perfumes, to make the necessary adaptations to changing fashion trends and to be able to meet the steadily increasing demand for odor enhancers for products of everyday use, such as cosmetics and cleaners.
In addition, there is generally a constant need for synthetic perfumes which can be favorably produced in a consistent quality and which have desirable olfactory properties, i.e. pleasant, near-natural and qualitatively new odor profiles of adequate intensity, and which are capable of advantageously influencing the fragrance of cosmetic and consumer products.
In this connection, the purity and hence the odor profile of synthetic perfumes are having to meet increasingly more stringent requirements. This means that the development of processes by which synthetic perfumes with improved purity and an improved odor characteristic can be obtained are acquiring increasing significance. These improved production processes generally have the additional advantage that the perfumes thus produced also show more favorable ecotoxicological properties by virtue of their greater purity.
At present, there is a particular demand among perfume experts for perfumes which have a pronounced musk odor characteristic.
4-tert.butylvinyl propionaldehyde and its .alpha.-methyl analog are known are possible perfume components from U.S. Pat. No. 626,548. According to U.S. Pat. No. 626,548, they can be obtained by hydroformylating .alpha.-methyl styrene with hydrogen and carbon monoxide in the presence of rhodium or cobalt catalysts.